(1) Field of the Invention
The invention is related to a method of providing an accurate volume-mass law for detection of precise fuel consumption of an engine, particularly providing an accurate volume-mass law for detection of precise fuel consumption of a helicopter engine.
(2) Description of Related Art
It is important for any aircraft crew to know precisely how much flight time is still available or to be able to determine how far it is possible to go and at which point it is compulsory to turn around in order to be able to return the take-off area. Long flights with flight sections without landing options, such as flights across the sea, above the jungle, desert or any other hostile areas make it compulsory for the crew of any aircraft to figure out exactly the mass of fuel necessary for an optimization of the mass to be lifted by the aircraft at take-off. With reduced allowances relative to the assessment of quantities while taking into account the different conditions the aircraft might encounter during its flight, e.g. direction and speed of the wind, precise metering means for the flow rate of the mass are necessary for an assessment of the remaining fuel quantity till landing and for the definition of a point of non-return.
The document GB828730 discloses the measure the rate of flow of fuel from the fuel tanks in an aircraft, in terms of mass rather than in terms of volume, for a better indication of the rate at which energy is being used since mass is not effected by changes in the ambient temperature. The flow rate is measured in gravimetric units with a moving coil meter of the dynamometric type, for measuring the volume rate of flow. A current is then passed in fixed coils to obtain results proportional to the density of the fluid. This involves integration of specific devices for metering the flow rate.
The document WO2011084940 discloses a sensor element in a fuel system, and in particular, to a potential electro-static differential level sensor element for measuring fuel levels and fuel type in a fuel system. A sensor element includes two electrode plates mounted on a dielectric material and secured to a shield plate. The sensor element is extruded to form a three dimensional sensor element, such as a spiral coil, that has increased capacitance detection ability to measure fuel type and level.
The document FR2945075 discloses a controlled high-pressure fuel flow which is fed into a combustion chamber via a valve, the position of which is controlled, and a shut-off and pressurization check valve with variable opening. A value representing the actual mass flow of fuel supplied is calculated by a computation unit from information representing the pressure difference between the input and output of the check valve and the clearance through the check valve, for example, resulting in the position X of the check valve slide. The valve has a variable position controlled by the computation unit according to the difference between the calculated value representing the actual mass flow and a value representing a desired mass flow. A sensor element recognizes the permittivity and from the permittivity the type of fuel in the system.